Hydrocarbon reserves are becoming increasingly difficult to locate and access, as the demand for energy grows globally. As a result, various technologies are utilized to collect measurement data and then to model the location of potential hydrocarbon accumulations. The modeling may include factors, such as (1) the generation and expulsion of liquid and/or gaseous hydrocarbons from a source rock, (2) migration of hydrocarbons to an accumulation in a reservoir rock, (3) a trap and a seal to prevent significant leakage of hydrocarbons from the reservoir. The collection of data may be beneficial in modeling potential locations for subsurface hydrocarbon accumulations.
Typically, reflection seismic is the dominant technology for the identification of hydrocarbon accumulations. This technique has been successful in identifying structures that may host hydrocarbon accumulations, and may also be utilized to image the hydrocarbon fluids within subsurface accumulations as direct hydrocarbon indicators (DHIs). However, this technology may lack the required fidelity to provide accurate assessments of the presence and volume of subsurface hydrocarbon accumulations due to poor imaging of the subsurface, particularly with increasing depth where acoustic impedance contrasts that cause DHIs are greatly diminished or absent. Additionally, it is difficult to differentiate the presence and types of hydrocarbons from other fluids in the subsurface by such remote measurements.
Current geophysical, non-seismic hydrocarbon detection technologies, such as potential field methods like gravity or magnetics or the like, provide coarse geologic subsurface controls by sensing different physical properties of rocks, but lack the fidelity to identify hydrocarbon accumulations. These tools may provide guidance on where in a basin seismic surveys should be conducted, but do not significantly improve the ability to confirm the presence of hydrocarbon seeps or subsurface hydrocarbon accumulations. Further, other technologies may include a remote vehicle to use optical sensing of an oil slick. See, e.g., Dalgleish, F. R. et al., Towards Persistent Real-Time Autonomous Surveillance and Mapping of Surface Hydrocarbons. OTC 24241, Houston: Offshore Technology Conference (2013). However, as such techniques do not obtain a sample, these techniques do not significantly enhance the ability to confirm the presence of hydrocarbon seeps or subsurface hydrocarbon accumulations.
Yet another technique may include monitoring hydrocarbon seep locations as an indicator of subsurface hydrocarbon accumulations. See, e.g., ASTM International, Standard Practices for Sampling of Waterborne Oils. D4489-95 (Reapproved 2011). However, these techniques are limited as well. These techniques may include remote monitoring to identify possible waterborne oil (e.g., oil slick) locations. This may be performed with satellite or airborne imaging of sea surface slicks. Then, a marine vessel can be deployed with a manned crew to determine the location of the slick and to obtain samples. However, the deployment of a marine vessel may be time consuming and expensive to deploy to the various locations. Further, the deployment may not be able to locate the oil slick. That is, the oil slick may have dissipated or moved to a different location as a result of changes in conditions, such as currents and/or wind. As such, conventional techniques are problematic and costly.
As a result, an enhancement to exploration and development techniques is needed. In particular, the exploration techniques used to locate potential seafloor seeps of hydrocarbons in a more accurate and cost-effective manner over conventional techniques are desired. These techniques may efficiently obtain samples from waterborne liquid hydrocarbons for indicators of a working hydrocarbon system in exploration areas, which may then be used to enhance basin assessment and to high-grade areas for further exploration.